Cancelled Stamps With Gum

I am sorting through my Czech stamps and notice the all have cancellation marks but on backside full gum like they've never been used? Is this a dumb question?

Not a dumb question. Quite a common one. Search the forum for "CTO" (cancelled to order). Some countries printed more stamps than could be used by residents for using on the mail, so the extras they "cancelled" and sold to stamp collectors. For some countries it became a big profit center especially when they started printing topical stamps about Disney or US presidents and other celebrities who had no relevance to the country printing the stamps.

https://goscf.com/t/83108

See: "Hinged and cancelled stamps with gum" where topic has been discussed.